There are 2 sizes... I got the 60cm. The other ones are 80cm. I couldn't see needing any more than 60, but there may be some jacked motherfuckers out there I'm not thinking about..

The thumb loop is cool. I'm not sure if other wraps have that, but it's easy as hell to get them on and off. I like taking them off between sets because when I put them back on before I go, my wrist just feels unbreakable. Definitely a good investment.